Dual purpose drafting machine



sept. 26, 1967 DUAL PURPOSE DRAFTING MACHINE Filed Sept. 15, 1965 3 Sheets-Sheet 1 v INVENTOR. JESSE DAVID woLF V "7 BY n ""J @WL ATTORNEYS J. D. WOLF 3,343,267

Sept. 26, 1967 J. D. WOLF l DUAL PURPOS DRFTING-MCHINE 's 'sheets-sheet 2 Filed Sept. 15; 1965 INVENTOR. JESSE DAVID WOLF ATTORNEYS sept. 26, 1967v v J. D. WOLF DUAL` FURPOSE DRFTING MACHINE 3 Sheets-Sheet 5 Filed Sept. l5, 1965 INVENTOR. JESSE DAVID WOLF ATTORNE YS United States Patent O 3,343,267 p DUAL PURPOSE DRAFTING MACHINE Jesse David Wolf, Aurora, Colo., assignor to Universal Drafting Systems, Inc., Denver, Colo., a corporation of Colorado Filed Sept. 13, 1965, Ser. No. 486,950 2 Claims. (Cl. 33--76) ABSTRACT F THE DISCLOSURE A drafting machine adapted for both conventional drafting and the development of isometric views from orthogonal views, and an improved head for such a machine. Th-e instrument head is suitably mounted to the drafting instrument in a manner to permit movement of said head in a plane parallel to a drafting board. The instrument head also includes a central axis and a pair of guide plates overlying each other and located beneath said head and .mounted for rotation about said axis throughout the full range of 360 degrees. Each guide pla-te contains la guide rule extending generally radially outwardly therefrom. Additionally, each guide rule ha`s a straight marker guiding margin intersecting a circular mar-gin portion formed on a base member of said instrument head, said straight marker guiding margin extending away from the point of intersection a-t an angle of 45 degrees to a radius of the head passing through the point of intersection. The overlappin-g portions of the overlying guide plates lare undercut on their confronting surfaces to reduce the combined thickness of such portions to the single thickness of other portions whereby the assembly is of uniform thickness throughout. Said guide plates include mounting means comprising'a disk-like skid plate of low-friction material secured to the bottom of said head.

This invention lies in the eld of drafting machines for use in making mechanical drawings, and is particularly directed to a dual purpose machine or instrument of this type. An instrument which incorporates some or all of the features of the invention is more suitable and versatile than the conventional drafting machine for use in ordinary or orthogonal drafting and in addition is adapted to be set for direct use in developing isometric views from orthogonal views.

My co-pending patent application, Ser. No. 376,841, filed June 22, 1964, now Patent No. 3,296,701, and entitled Mitering Drafting Machine for the Development of Isometric Views, discloses and claims a novel apparatus which is specifically adapted for use in developing isometric Views and is not well suited for conventional draftin-g work. The present application discloses an invention in which the same elements may be adjusted to one position for use in conventional drafting and to another position for isometric development work, thus eliminating the need to interchange either the marker guide rules or the entire drafting head as in prior art devices.

The machine disclosed herein incorporates some of the features of my co-pending application, including a horizontal track preferably mounted at the upper margin of a drafting board, and a vertical track extending downward across the height of the board. The connection between them permits the 4vertical track to be moved horizontally across the width of the board or to be swung angularly about 30 degrees to either side of vertical. The vertical track may be locked in any lateral or angular position. A third generally lateral or horizontal arm is mounted at one end to the vertical track and is movable along the length of the latter. Its other end is adapted to be connected to a drafting instrument head. These three elements generally constitute a con trol arm by means of which the instrument head may be located at any selected position on the board, and its movement therefrom may be controlled in any one of several linear directions or it may be controlled to move parallel to itself in any direction without change of its angular relation to a selected reference line such as a margin of the board.

Generally stated, the improved instrument comprises a head and a pair of angularly adjustable guide rules. The head includes a body portion having means for attachment to the free end of the control arm to move therewith but it is restrained against angular rota-tion in a plane parallel to the surface of the board. The head includes an annular base plate or member mounted beneath the body portion, and the pair of guide rules are extensions of a pair of guide plates rotatably mounted beneath the base plate for rotation about an upright axis extending -generally centrally through the head. Each guide plate can be adjusted to any angular position throughout the entire 360 degree range, and each guide plate is provided with brake means to lock it independently to the base pla-te. Thus, for conventional drafting the guide plates are locked so that one guide rule is horizontal and one is vertical. For isometric construction the two guide rules are set at equal angles to the horizontal with an included angle of the order of degrees. While other angles may be used, these angles have been found to be very satisfactory for this particular operation.

In the simplest form of the new construction, the base plate may be fixed to the body portion of the head. However, to obtain maximum exibility and facilitate various techniques, the base plate or member is preferably made as an annular protractor plate also rotatable about the upri-ght axis of the head and provided with brake means to lock it to the body portion in any angular position of adjustment. Since the guide rules can be locked to the protractor plate, the three elements may be rotated as a unit about the upright axis of the head.

The guide rules comprise g-uide blades and guide arms which may be integral for simplicity or the guide blades may be detachable. In the latter case, guide blades may be substituted which are even more useful for isometric work, having opposed marker guiding margins which are linear and set at outwardly converging angles of about 15 degrees.

Various other advantages and features of novelty will become apparent as the description proceeds in conjunction with the accompanying drawings in which:

FIGURE l is a schematic plan View of a drafting board on which is mounted a dual purpose drafting machine incorporating the features of the invention;

FIGURE 2 is a plan view of the new drafting instrument head and guide rules;

FIGURE 3 is an elevational view of the head with the base member, guide plates, and attaching means in section;

FIGURE 4 is a sectional view taken on line 4-4 of FIGURE 1 showing a detail of a drafting rule and its accessory; v

FIGURE 5 is a sectional view taken on line 5--5 of FIGURE 4;

FIGURE 6 is a plan View of an alternative form of guide blade; and

FIGURE 7 is a plan view similar to FIGURE 2 showing the guide rules in position for conventional drafting.

A complete drafting machine assembly incorporating the invention is shown in FIGURE 1 mounted on a conventional rectangular drafting board 10, and comprises a lfirst group 12 constituting a control arm and a second group 14 constituting a drafting instrument. The control arm is substantially identical with the one disclosed in my prior application, Ser. No. 376,841, mentioned above, in which the details of construction and operation are fully outlined. Generally speaking, it comprises a horizontal track 16, a vertical track 18 and a horizontal arm 20. Track 16 detachably secured to the upper margin of the board by suitable brackets 22, is hollow and open at its lower side to provide an end-to-end guide for a wheeled carriage, not shown, to which is secured a dolly 24. A second wheeled carriage 26 is pivotally mounted on the dolly for rotation about an upright axis indicated at 28.

Track 18 is of the same general construction as track 16 and is mounted on carriage 26 for movement in the direction of its longitudinal axis. In addition, because of the pivotal mounting of carriage 26, track 18 may be swung to either side of its vertical position an angular distance of about degrees as indicated by dotted lines 30.

A third wheeled carriage 32 is mounted under and within track 18 for movement along the longitudinal axis of the track, and is provided with a rigid extension 34. Arm 20 is provided at its left end, as viewed in FIGURE 1, with a standard pivot clamp 36 for connection to the extension in a plane parallel to the board.

Instrument 14 is provided with la head 38 which includes a body portion 40. The latter, in turn, has an integral pivot clamp 42 which connects to the free end 44 of arm 20 to provide for angular movement toward and away from the board while preventing relative angular movement between body portion and arm 20 in a plane parallel to the board.

Brake means, not shown, are provided to releasably lock dolly 24 against movement along track 16, to lock carriage 26 against angular movement with respect to dolly 24, to lock track 18 against longitudinal movement with respect to carriage 26, and to lock carriage 32 against longitudinal movement in track 18. Since the brake means are all selectively operable, the control arm can be operated in a variety of ways to facilitate various drafting needs. With the elements in the position shown, the horizontal carriage may be released and the instrument 14 may be moved horizontally without change in angular or vertical position. With the vertical carriage 32 released, the instrument may be moved vertically without change in angular or horizontal position. Additionally, track 18 may be swung to an angular position and locked, and arm 20 and the instrument may then be moved generally vertically parallel to the axis of track 18 without other change. This is particularly useful in isometric construction. When track 18 is swung to an angular position it can be released and moved downwardly with respect to dolly 24 in order to extend fully to the lower margin of the board.

The drafting instrument and its associated parts are shown in more detail in FIGURES 2 and 3, in which head 38 may be substantially identical with one of the standard drafting machines currently on the market, although various elements may be eliminated without loss of flexibility. The head includes a handling knob 46 as well as the body portion 40, which latter has an enlarged generally planar skirt 48. Beneath the skirt and extending radially beyond it is an annular base member or plate 50.

While the base member may be integral with or lfixed to the body portion it is preferably formed as a protractor plate mounted for rotation about an upright axis 52 passing generally centrally through head 38. To this end, a central shank 54, having a reduced portion 56, protrudes downwardly from the body portion on axis 52. Plate is recessed at 58 on its upper surface and provided with a central aperture 60 for pivotal mounting on shank 54.

Skirt 48 is provided on its periphery with an annular bead 62 for engagement by guiding and locking elements on base member 50. Diametrically opposed guide strips 64 and 66 are secured to member 50 by screws 68 and are provided with flanges 70 overlying bead 68 to assist in maintaining the skirt 48 and base member 50 in assembled relation. Suicient clearance is provided between the flanges and the bead to permit free rotation of member 50 about its axis. In addition, a brake member 72 of the same construction as the guide strips is located adjacent to guide strip 66 and is secured by thumb screw 74. In this case, the thickness of the brake member is somewhat reduced and the thumb screw can be turned down sufficiently to engage brake member 72 with bead 62 and lock base member 50 against rotation at any angular position throughout a range of 360 degrees. Skirt 48 is provided with angular scale markings about its periphery as indicated at 76, and guide strip 66 is provided with a cooperating vernier scale 78.

The marker guiding members which make the instrument particularly suitable for isometric construction include left and right hand guide plates and 82 provided with guide rules 84 Iand 86 respectively extending outwardly therefrom. The guide rules may be unitary or they may be composed of guide arms 88 and 90 integral with the guide plates, with guide blades 92 and 94 detachably secured thereto. The main body portion of each guide plate is generally annular and their confronting surfaces are undercut as indicated at 96 and 98 so that their cornbined thickness is equal to the thickness of the other por tion of each guide plate. The overlapped portions are provided with central apertures 100 and 102 for pivotal mounting beneath base plate 50 to rotate about axis 52. They are held in place and pivotally mounted on a skid plate 104 of generally disk-like form and made of a lowfriction material, preferably nylon. The skid plate has a bearing portion 106 and an annular flange 108. It is provided with a central counterbore 110 press-fitted on shank portion 56 and secured by screw 112.

The periphery of base member 50 is provided with an annular bead 114 and each guide arm is provided with a guide strip 116 having a flange 118 overlying the bead to hold the parts in assembled but freely rotatable relation in the same manner as base 50 and skirt 48. Each guide strip is held to its guide arm by screws 120 and is provided with a Vernier scale 122 to cooperate with the degree scale 124 on the margin of member 50. In addition, each guide arm is provided with a brake strip 126 having a ange 128 bearing on bead 114, and a thumb screw 130 to urge the brake strip into binding engagement with the bead to lock its respective guide plate in any angular position throughout the full range of 360 degrees.

Guide rules 84 and 86 extend outwardly from their respective guide plates in a direction which may be described as generally radial. However, this direction is somewhat modified as shown to increase the utility of the instrument. Whether the rules are unitary or separable, they have at least one marker guiding margin, 132 and 134, which is linear and which extends from the end of the rule to a point of intersection 136 with the circular margin portion of the head, which in this case is base member or protractor plate 50. The marker guiding margin extends at an angle of 45 to a radial line 138 passing through point 136. The margins diverge from each other at opposite sides of such radial line. A very desirable result of this angular divergence is that the inner ends of the rules are much closer to each other when set in the positions of FIGURE 2 for isometric work than they would be if they extended on true radial lines. In the latter case, they would be separated by almost the full width of the head.

The configuration described above also provides added advantages when the instrument is used in conventional or orthogonal drafting. The schematic View in FIGURE 7 shows head 38 with its rules 84 and 86 adjusted to the usual vertical and horizontal positions. It will be observed that the marker guiding margins are straight and continuous all the way in to the mutual point of intersection 136. Thus it is possible to operate a pencil or other marker in a continuous movement to produce square cornered outlines rather than to have to shift the head and rules several times to accomplish the same thing. Moreover, rule 84 can be swung around to the dotted line position shown in FIGURE 7 in which its marker guiding margin is almost parallel to that of rule 86. In fact, by shortening the peripheral extent of the guide arms slightly, it is possible to achieve parallelism. Thus, with a choice of using either margin of each rule, the instrument may be set quickly and simply to provide any included angle desired.

While it is true that the rules of most conventionalV drafting machines are mounted so that they canbe angularly adjusted, the angular range is quite small, usually of .the order ofdegrees, which seriously limits their utility.

Furthermore, the rules are pivoted at points outside the perimeter of the head and have no protractor markings or such small ones that they cannot be set accurately. Consequently, the usual procedure is to set them by reference to an independent protractor, which is clumsy, diicult, and time consuming. In contrast, each rule of the present invention, being pivoted about the axis of the head, can be set by reference to the protractor markings 124 on the periphery of plate 50, which can be made as large as desired, and they are further provided with the Vernier scales 122 which facilitate extremely accurate setting.

Each of the guide rules 84 and 86, whether of the unitary or two-piece type, is provided with longitudinally extending slots 140 through their thickness for slidably mounting auxiliary rules 142. The latter have marker guiding margins extending perpendicular to the margins of the main rules and are highly useful adjuncts in isometric construction. The manner of mounting them is illustrated in FIGURES 4 and 5, where it will be seen that rule 86 is provided on its underside with a deep, rectangular channel 146 extending lbeneath and communicating with slot 140 from end to end.

Mounted in the channel is an elongate slide block 148 adapted to slide in contact with one side wall of the channel. It is maintained in proper position by the action of pressure plate 150 bearing against the opposite side wall of the channel. The block and plate are urged resiliently apart by springs 152 surrounding slidable guide pins 154 and seated in sockets 156. A pair of longitudinally spaced mounting Shanks 158 are secured to the slide block and extend upwardly through slot 140, having sliding clearance therein. The base 144 of the auxiliary rule has matching apertures 160 which fit down over the Shanks so that the base directly overlies the upper surface of the rule 86.

A keeper plate of spring material 162, preferably slightly concave downwardly, is provided with a pair of keyhole slots 164. The enlarged portions fit over the full diameters ofthe shanks so that the keeper plate is pressed down at against the base 144 and then moved longitudinally to engage the reduced portions 166 of the key-hole slots with the annular grooves 168 in the shanks to lock the assembly in place. A reverse operation of the keeper plate renders the assembly quickly removable when the auxiliary rule is not needed.

When the instrument is provided with two-piece rules, the guide blades 92 and 94 may be removed from guide arms 88 and 90 and replaced by special guide blades more fully adapted for isometric construction. The guide blade 170 illustrated in FIGURE 6 is a typical example. It is a right hand blade generally comparable to one half of the modified guide rule of my prior application above referred to. When a matched pair of such guide blades is substituted for conventional ones the instrument can be used in the same Way as my previous instrument.

Guide blade 170 is provided with a standard chuck connection 172 cooperating with a standard chuck jaw on the underside of one of the guide arms. It is provided with a first marker guiding margin 174 and with a slot 176 adapted for slidable mounting of the auxiliary rule 142 in the same manner as guide rule 86. Itis also provided with a second marker guiding margin 178. Both margins are straight or linear and they converge outwardly at an angle of the order of 15 degrees, an arrangement which has been found particularly suitable for isometric construction.

From the above description and explanation it can be seen that the drafting machine of the present invention performs all of the functions of both conventional and isometric drafting which require two distinct and different prior art machines and is more flexible and useful than either of the prior art types.

It will be apparent to those skilled in the art that van'- ous changes and modifications may -be made in the construction and arrangement of parts of the machine herein disclosed without departing from the spirit of the invention, and it is intended that all such changes and modications shall be embraced within the scope of the following claims.

I claim:

1. A drafting machine adapted for both conventional drafting and the development of isometric views from orthogonal views, comprising: control arm means adapted to be secured to a drafting board and having a free end adapted to be moved over the surface of a drafting board without angular change with respect to a margin of said board; an instrument head having a body portion adapted to be secured to said free end for movement therewith and without angular change with respect to said margin, said head having a generally central axis normal to the plane of said board, said head including a base member in the form of a protractor plate located beneath said Ibody portion and mounted thereto for rotation about said axis; brake means to lock said plate in selected angular relation to said body portion; a pair of guide plates overlying each other and located beneath said protractor plate and mounted for rotation about said axis throughout the full range of 360 degrees, the overlapping portions of said guide plates being undercut on their confronting surfaces to reduce the combined thickness of such portions to the single thickness of other portions whereby the assembly is of uniform thickness throughout, said guide plates having bearing apertures concentric with said axis, the mounting means for said guide plates comprising a disk-like skid plate of low-friction material secured at the bottom of said head; a guide rule extending generally radially outward from each guide plate, each guide rule having a straight marker guiding margin intersecting the protractor plate of said head wherein said straight marker guiding margin extends away from the point of intersection at an angle of 45 degrees to a radius of said head passing through said point of intersection, said margins of the two guide rules diverging to opposite sides of said radius whereby when said guide rules are set at right angles to each other their margins will`intersect to provide continuous guiding means for a drafting marker; each of said guide rules having a pair of opposed marker guiding margins one of which is said straight marker guiding margin, said opposed margins being straight and being at an angle of the order of l5 degrees to each other and converging outwardly, each of said guide rules being formed with a slot through its thickness extending longitudinally of the rule; a supplementary marker guide detachable mounted in each slot and slidable along its length, each marker guide having a longitudinal axis extending at right angles to the axis of its respective guide rule; and brake means to lock each guide plate independently in any selected angular relation to said head.

2. A drafting machine as described in claim 1 in which said skid plate includes an angular journal surface to fit said bearing apertures and provide a pivotal support for said guide plates and having an annular flange below said journal surface to retain said guide plates in position; each of said guide rules comprising a guide arm integral with its respective guide plates and a guide plate detachably connected to said guide arm for ready interchangeability; and at least one marker guiding margin of each guide plate being in linear alignment with a margin of its respec- 7 8 tive guide arm to provide continuity of guiding means and 142,730 10/ 1953 Sweden. extend said guiding margin, when positioned for isometric 181,528 3/ 1955 Austria. work, closer to the center of instrument head. 761,930 11/ 1956 Great Britain.

1,186,549 2/ 1959 France. References Cited 5 1,000,604 1/ 1957 Germany. 5 UNITED STATES PATENTS OTHER REFERENCES 1 l; grlllmaker 33 79 The New Universal Boardmaster, by Universal Draft- 1- FOREIGN PATENTS l0 LEONARD FORMAN, Pl'l'lnly Exdnl'fle.

608,937 2/1935 Germany, H. N. HAROIAN, Assistant Examiner. 

1. A DRAFTING MACHINE ADAPTED FOR BOTH CONVENTIONAL DRAFTING AND THE DEVELOPMENT OF ISOMETRIC VIEWS FROM ORTHOGONAL VIEWS, COMPRISING: CONTROL ARM MEANS ADAPTED TO BE SECURED TO A DRAFTING BOARD AND HAVING A FREE END ADAPTED TO BE MOVED OVER THE SURFACE OF A DRAFTING BOARD WITHOUT ANGULAR CHANGE WITH RESPECT TO A MARGIN OF SAID BOARD; AN INSTRUMENT HEAD HAVING A BODY PORTION ADAPTED TO BE SECURED TO SAID FREE END FOR MOVEMENT THEREWITH AND WITHOUT ANGULAR CHANGE WITH RESPECT TO SAID MARGIN, SAID HEAD HAVING A GENERALLY CENTRAL AXIS NORMAL TO THE PLANE OF SAID BOARD, SAID HEAD INCLUDING A BASE MEMBER IN THE FORM OF A PROTRACTOR PLATE LOCATED BENEATH SAID BODY PORTION AND MOUNTED THERETO FOR ROTATION ABOUT SAID AXIS; BRAKE MEANS TO LOCK SAID PLATE IN SELECTED ANGULAR RELATION TO SAID BODY PORTION; A PAIR OF GUIDE PLATES OVERLYING EACH OTHER AND LOCATED BENEATH SAID PROTRACTOR PLATE AND MOUNTED FOR ROTATION ABOUT SAID AXIS THROUGHOUT THE FULL RANGE OF 360 DEGREES, THE OVERLAPPING PORTIONS OF SAID GUIDE PLATES BEING UNDERCUT ON THEIR CONFRONTING SURFACES TO REDUCE THE COMBINED THICKNESS OF SUCH PORTIONS TO THE SINGLE THICKNESS OF OTHER PORTIONS WHEREBY THE ASSEMBLY IS OF UNIFORM THICKNESS THROUGHOUT, SAID GUIDE PLATES HAVING BEARING APERTURES CONCENTRIC WITH SAID AXIS, THE MOUNTING MEANS FOR SAID GUIDE PLATES COMPRISING A DISK-LIKE SKID PLATE OF LOW-FRICTION MATERIAL SECURED AT THE BOTTOM OF SAID HEAD; A GUIDE RULE EXTENDING GENERALLY RADIALLY OUTWARD FROM EACH GUIDE PLATE, EACH GUIDE RULE HAVING A STRAIGHT MARKER GUIDING MARGIN INTERSECTING THE PROTRACTOR PLATE OF SAID HEAD WHEREIN SAID STRAIGHT MARKER GUIDING MARGIN EXTENDS AWAY FROM THE POINT OF 